Rules
You enter a Prestiege Class by taking a multiclassing feat, just as you would any other class. However, this feat can never be retrained. Once you go into a Prestiege class, you're stuck there. These feats may have prerequisites, and you must meet these before you can take it, just like any other feat.
Unlike normal numticlassing, where you gain some class features straight away, Prestiege classes grant you benefits based on your level. Note the level at which you take the Prestiege feat. This will be listed as "Level". There will be abilities with "Level + X" written beside them. You gain these abilities when you reach the appropriate level.
Unlike normal numticlassing, where you gain some class features straight away, Prestiege classes grant you benefits based on your level. Note the level at which you take the Prestiege feat. This will be listed as "Level". There will be abilities with "Level + X" written beside them. You gain these abilities when you reach the appropriate level.
Example
You go into a Prestiege class at level 5. There is an ability that you gain at Level + 4. Therefore, you gain the ability at level 9
Of course it just makes the classes unpredictable. So these thinmgs take the place of a multiclass feat? What about having them get their own class of feat? (An eldritch knight won't exactly be a straight fighter or mage...)
1) Spread these benefits out over multiple feats. No matter which tier you select these feats at, they are incredibly powerful. Your Arcane Archer example, for instance, combines two feats and one excellent bonus into a single feat slot over the course of a mere four levels: Longbow proficiency (Weapon Proficiency), +1 damage with longbows (Weapon Focus), and +1 attack with longbows (no feats give attack bonuses, which are far superior to damage bonuses). This is too powerful for a single feat, and should be spread out.
2) Place serious requirements on these feats. The given requirement for Arcane Archer, for example, is trivial to accomplish. If these feats do represent some particular aptitude, as 3E prestige classes were designed to express, then they should have requirements commensurate to that aptitude.
3) The inevitable response to my previous points is, "How would these be different from normal feats and paths if I made these changes?" The answer is, they wouldn't be. Not fundamentally, at any rate. Paragon paths fill much the same role as 3E prestige classes - they specialize a character, differentiating Thalis the Render from other elven rangers of a similar level. To build a character that would fill the niche that your Arcane Archer occupies, I would do the following. First, create a ranger (ideally) or a rogue. Next, take a multiclassing feat or three to shift around my powers to include more Arcane power source abilities. Fill out the rest of my feats with ranged weapon options, like Weapon Focus or Sly Hunter. Finally, work with my DM to create a homebrew Arcane Archer path which would provide some of the classic Arcane Archer abilities (Fireball-laden arrows, for example) within the existing framework.
All of the tools to create interesting, viable prestige classes are available in 4E already without these sorts of circumlocutions around the RAW. Things don't work the same, but they do seem to work well.
Interesting idea, although I think that your current approach will lead to these overpowering other feats. Thoughts and tweaks:
1) Spread these benefits out over multiple feats. No matter which tier you select these feats at, they are incredibly powerful. Your Arcane Archer example, for instance, combines two feats and one excellent bonus into a single feat slot over the course of a mere four levels: Longbow proficiency (Weapon Proficiency), +1 damage with longbows (Weapon Focus), and +1 attack with longbows (no feats give attack bonuses, which are far superior to damage bonuses). This is too powerful for a single feat, and should be spread out.
Making it broken was my main concern, and while I thought it was broken, it's always nice to have a second opinion.
With spreading the benefits out across several feats, could you simply then say that, instead of having a whole "multiclass" thing, just have the feat for say, arcane archer, and then have that feat as a prereq for all the other benefits, while having level restrictions on when you can take those feats (similar to the "Level + X" idea)?
2) Place serious requirements on these feats. The given requirement for Arcane Archer, for example, is trivial to accomplish. If these feats do represent some particular aptitude, as 3E prestige classes were designed to express, then they should have requirements commensurate to that aptitude.
Noted
.3) The inevitable response to my previous points is, "How would these be different from normal feats and paths if I made these changes?" The answer is, they wouldn't be. Not fundamentally, at any rate. Paragon paths fill much the same role as 3E prestige classes - they specialize a character, differentiating Thalis the Render from other elven rangers of a similar level. To build a character that would fill the niche that your Arcane Archer occupies, I would do the following. First, create a ranger (ideally) or a rogue. Next, take a multiclassing feat or three to shift around my powers to include more Arcane power source abilities. Fill out the rest of my feats with ranged weapon options, like Weapon Focus or Sly Hunter. Finally, work with my DM to create a homebrew Arcane Archer path which would provide some of the classic Arcane Archer abilities (Fireball-laden arrows, for example) within the existing framework.
I guess. Maybe, instead of trying to keep everything from Prestiege Classes, I should just start converting all the ones I want into Paragon Paths?
All of the tools to create interesting, viable prestige classes are available in 4E already without these sorts of circumlocutions around the RAW. Things don't work the same, but they do seem to work well.